Turns out that rather poor quality Jet is found in the US, which is probably where Walker Audio source the stuff. 8 brass machined cups with a fragment of Jet in the bottom of each are $590 (so about £50 a pop).
Or even
https://walkeraudio.com/?product=tal...etic-optimizer . Who knew that vinyl records, CDs and screened wire were magnetic?
I've discovered something new in physics thanks to Walker! Here was I (silly me) thinking that polymers were weakly diamagnetic as a result of having closed atomic shells through covalent bonding.